This invention relates to spinners and particularly for fan jet engines.
Conventionally, the spinner serves to provide a smooth aerodynamic wall surface to not only cover the mechanism in a rotating machinery, such as the hub and shaft of a fan jet engine but also defines a contour for directing the air flow and heretofore was never utilized as a structural member. Accordingly, it is customarily made out of nonstructural material, such as sheet metal, molded glass fibers or other composite material.
I have found that I can achieve the customary spinner function and also achieve certain advantages in the engine operation and performance by manufacturing the spinner outer body from a suitable material having high resilience and strength and preloading it so that it loads the fan rim. Thus, I am able to obtain the following advantages:
1. Fan stage weight is optimized in obtaining the necessary stage vibratory and flutter design goals.
2. Foreign object damage in the area of the spinner is reduced.
3. The spinner provides a fail-safe mechanism for fan blade retention in the event of tablock failure.